JPH07300790A - Double sheave part - Google Patents

Abstract

PURPOSE: To provide a double sieve section designed to exclude the occurrence of 'sharp-pointed waterline'. CONSTITUTION: This double sieve section formed by 1st and 2nd sieves D1 and D2 and having 1st and 2nd endless sieves for forming a fiber material web of a fiber suspension, notably for forming a ply of a multiply paper or cardboard web, the ply being merged on a 3rd sieve with a further ply, is such one that a dewatering box that features rigid slats is contained in the loop of the one sieve, while in the loop of the other sieve there are contained several backing slats which can be pushed flexibly on the other sieve, while a loop of one of the two sieves contains a forming roll which together with this sieve form a looping zone; wherein the forming roll has a smooth, continuous roll shell, and the sieve which in the looping zone is outside separates from the web and the inner sieve at a distance before the end of the looping zone.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a strip fiber material comprising a fiber suspension, and in particular to a double sheave section for forming layers of multiple webs or strips of cardboard.

[0002]

2. Description of the Related Art German Patent Publication No. 40310
No. 38 is referred to.

The above-mentioned publication discloses a double-sheave former, the double-sheave section of the former starting with a first group of dewatering bars and then transferred to the forming rollers, in which case , The double-sheave area runs over the forming rollers and at the end through a suction box, behind which box both double-sheaves are separated. Such an arrangement seeks to obtain as high a web water content as possible on leaving the forming roller in order to achieve a high gap stability of the multilayer web. In this case, there is a risk that in the "pointed water line" in the taper described in the publication, a significantly moist material will reach and be compressed at the dehydration compression point.

US Pat. No. 4,207,144 discloses a raw material charging part, a pre-dewatering section formed from the raw material charging part and consisting of only one sheave, said sheave and the outer side covering it. And a double sheave section formed from the sheave of the papermaking machine. Such devices have scrapers only in the pre-dewatering zone. However, this device does not have a rigid dewatering bar in one sheave loop, nor a flexible dewatering bar in the other sieve loop.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a double sheave portion which prevents the occurrence of the sharp water line.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide a strip fibrous material, in particular of a multi-layer, consisting of a fiber suspension, in which the layer in the third sheave is adapted to be guided together with another layer. First for forming a layer of web or strip cardboard
A double sheave portion having an endless sheave and a second endless sheave, the first sheave and the second sheave
In the double-sheave area formed by the sheaves of one of the sheaves, there is a spin-drying box in the loop of one sheave, which spin-drying box has a rigid bar in contact with one sheave and the other. Within the loop of the sheave there is some support bar that is bendable and crimpable to the other sheave, as well as within one loop of both sheaves forming rollers which together with this sheave form a winding area. In the double sheave part where is present,
The forming roller has a smooth closed roller peripheral surface such that the outer sheave in the winding area is spaced apart from the web and the inner sheave before the end of the winding area. It is solved by featuring that. This means that the taper on the forming roller is significantly dewatered, ie the sharp water lines are straightened and the material, which is too damp, does not reach the dewatering compression point. Furthermore, an arrangement which provides a significant reduction in the structural height and thus a cost-saving effect is described in claims 4-12. In addition, claim 17
Describes an extremely short structural length and a structurally advantageous arrangement in the structure, in which the lower sheave is in the substrate and the removal point is directly above the bottom of the papermaking machine. positioned.

[0007]

An advantage of the present invention is that the outer sheave is unwound from the forming roller before the inner sheave so that the double sheave section does not end directly at the forming roller but at a distance behind it. is there. Since the forming rollers are smooth and not open, the web runs reliably with the inner sheave. As a result, in such a configuration, the sheaves are released before, for example, a slippage between the webs due to the difference in tension between the sheaves results in a risk of web damage due to the minimum speed difference between the sheaves. Is extremely low.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to FIGS.

FIG. 1 shows a double sieve former according to the invention in connection with a vertical sieving machine for producing a two-layer web. A longitudinal sheave L is shown in the lower region, on which the first paper layer is produced by dewatering one side in a known manner. in addition,
A double-sheave former according to the invention having a first sheave D1 and a second sheave D2 is arranged. The first sheave D1 charged with the raw material suspension via the raw material charging unit STA dehydrates the charged raw material suspension over the pre-dehydration section VE. Behind the pre-dewatering section VE, the first sheave D2 is fed via a swivelable roller, in which case both sheaves D1 and D2 subsequently enclose the pre-dehydrated feed suspension in a sandwich. , And a dewatering bar extending across the width of the web guides dewatering on both sides. Such double-sided dehydration can be done in any known manner. For example, a plurality of stationary bars are attached to the upper side, and a dehydration bar that is elastically pressed against the opposite side is provided in the gap between these bars. Following this dewatering section ZE on both sides, the web guided between the double sheaves is guided via a forming roller FW having a smooth surface, in which case the sheave D2 is separated from the web while the sheave D1 is still It abuts the forming roller FW, which ensures that the web stays securely on the sheave D1. The paper layer dewatered in this way is brought by the sheave D1 through another roller into the layer produced on the longitudinal sheave. After a further lapse, the double sheave is removed from both combined paper layers and guided back again, while both paper layers remain on the longitudinal sheave and are conveyed to the next processing station.

FIG. 2 schematically shows a configuration similar to that of FIG. In this case as well, the corresponding reference numerals are attached. The difference between the double-sheave part of FIG. 1 and the double-sheave part of FIG. 2 is mainly in the construction of the dehydrating parts ZE on both sides. In FIG. 2, a flat dewatering section on both sides formed by opposing dewatering bars is followed by a stationary dewatering bar with a row of stationary dewatering bars arranged in the loop of sheave D2. The bar gives the double sheave an upwardly curved course.

FIG. 3 likewise shows an arrangement similar to that of FIGS. 1 and 2, with the only difference that behind the flat double-sided dewatering section ZE is a downwardly curved formation in the loop of the sheave D1. Shoe FS is connected,
Further, the forming roller FW follows the forming shoe.

In the state of the sheave portion shown in FIG. 4, since the raw material suspension is charged into the first sheave D1 through the raw material charging section, a double-layered web is also produced. The front dewatering unit VE starts dewatering one side of the first layer. When the sheave D1 further passes, the second sheave D2 is supplied from above, and the second sheave confines the newly formed first layer in a sandwich shape to form the dehydration portions ZE1 on both sides.
The strip-shaped double sheave consisting of sheaves D1 and D2 is then fed to a forming roller FW having a smooth surface, from which sheave D
1 are separated in the manner according to the invention, while the sheave D2 is still abutting the surface, so that the web runs further with the sheave D2. The sheave D2 is then fed via another diverting roller to a second raw material charging part for charging a new raw material suspension onto the already formed web and is transferred directly to the second double sheave part. To be done. Both paper layers are then further guided to a delivery point to band B, which continues to be located on sheave D2 after dewatering has taken place.

FIG. 5 shows a state similar to FIG.
In this case, however, the curved forming shoe FS shown in FIG. 3 is replaced by a one-sided dehydration part via a rigid bar in the dehydration box E, which gives rise to a linear course of the sheaves. . In addition, the straight pre-dewatering section VE is omitted, and the raw material suspension is introduced directly between the sheaves D1 and D2 traveling via the breast rollers BW, corresponding to the gap-former. It

FIG. 6 shows a double-sheave part according to the invention for producing a two-layer paper, in this case the first
The raw material suspension is charged into the sheave D1 and is pre-dehydrated over the pre-dehydration section VE. This sheave D1 is fed with a second sheave D2 from above behind the front dehydration section VE, so that both sheaves D1 and D2 confine the resulting web in a sandwich. Directly to the collecting section of both sheaves D1 and D2, the dehydrating section Z on both sides
E1 is connected, and a sheave extending in a sandwich shape is guided around the forming roller FW behind the dehydrating section. The sheave D1 is separated from the web and the sheave D2, while the sheave D2 is still abutting on the forming roller FW, so that the web remains on the sheave D2. The sheave D2 is fed to the second double-sheave part together with the first layer of the web lying above it, in this case
Fresh raw material is introduced into the gap formed by the sheave D2 and the sheave D3 coming from above through the raw material charging section. At the beginning of the gap that causes the first dewatering of the freshly-supplied feed suspension, the breast roller BW is moved to the sheave D2.
It is provided in the loop. Breast Roller BW
It can also be configured as a suction roller. Behind the breast roller, the newly formed double sheave consisting of sheave D2 and sheave D3 has a double-sided dehydration section ZE.
2, in which case the dewatering bar is elastically crimped, for example elastically, to the sheave D2 in the loop of the sheave D2, whereas the dewatering bar arranged in the sheave D3 is stationary. Behind the dewatering section ZE2 on both sides, the double sheave is guided along a dewatering box E with a stationary dewatering bar in the loop of the sheave D2, then the sheave D2.
And the separating suction TS that allows the web located thereabove to be safely separated from the sheave D3.
Will be guided along. The sheave D2 then guides the web further to the delivery point, where the web is band B.
Will guide you to the next processing section.

According to the invention, the outer sheave is paid out of the forming roller before the inner sheave, so that the double-sheave area does not end directly at the forming roller but at a distance behind it. In addition, since the forming roller is smooth and is not open, in a configuration in which the web travels securely with the inner sheave, a difference in tension between the two sheaves causes a gap between the web and the sheave. Since the sheaves are released before, the risk of web damage due to the minimum speed difference between both sheaves is very low, thus providing a double sheave section which prevents the formation of sharp water lines.

[Brief description of drawings]

FIG. 1 is a schematic view showing a double sieve former according to the present invention.

FIG. 2 is a schematic view showing a modified embodiment of the double sieve former according to the present invention.

FIG. 3 is a schematic view showing a modified embodiment of the double sieve former according to the present invention.

FIG. 4 is a schematic view showing a modified embodiment of the double sieve former according to the present invention.

FIG. 5 is a schematic view showing a modified embodiment of the double sieve former according to the present invention.

FIG. 6 is a schematic view showing a modified embodiment of the double sieve former according to the present invention.

[Explanation of symbols]

 L longitudinal sheave, D1 first sheave, D2 second sheave, D3 sheave, STA raw material charging section, VE pre-dewatering section, ZE, ZE1, ZE2 dewatering section, FW forming roller, FS forming shoe, B band, BW Breast roller, E dehydration box, TS separation suction.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Rickert Konrad Germany 89555 Steinheim Schumannstrasse 19

Claims (18)

[Claims] 1. A band-like fibrous material consisting of a fiber suspension, in particular a layer of a multi-layered web or cardboard, in which the layers in the third sheave are adapted to be guided together with another layer. A double sheave portion having a first endless sheave and a second endless sheave, for the purpose of: 1.1 in a double sheave area formed by the first sheave and the second sheave, There is a dehydration box in the loop, which has a rigid bar that contacts one of the sheaves,
And in the loop of the other sheave there is some support bar that is bendable and crimpable to the other sheave, and in one loop of both sheaves forms a winding area with this sheave In the double-sheave part where the forming roller is present: 1.2 The forming roller has a smooth closed roller circumference, 1.3 The outer sheave in the winding area is located before the end of the winding area. A double sheave portion characterized by being spaced apart from the web and the inner sheave. 2. The double sheave portion of claim 1 having a gap-former. 3. The double sheave portion of claim 1, which is a hybrid-former having a long lower sheave and a short upper sheave. 4. One sheave (upper sheave)
Is traveling through a sheave roller supported by a swivel lever in a double sheave area, 4.2 The dewatering box is fixed to the swivel lever and is thereby swivelable with the sheave roller. The double sheave part according to claim 3. 5. The slewing bearing used for bearing of the slewing lever is arranged at a short distance from the plane of formation of the lower sheave and downstream of the spin-drying box, 5. The double sheave portion according to claim 4, wherein the outer end of the two-swivel lever that supports the bearing of the sheave roller is supported by the frame of the lower sheave or the gate-shaped member that engages from above. 6. The double-sheave portion according to claim 5, wherein the outer end of the pivot lever rests on a support device which is varied in height. 7. The double sheave portion according to claim 5, wherein the swiveling lever has a substantially L-shaped lateral shape. 8. The double sheave section of claim 7, wherein the pivot axis is located at the end of the short leg and the sheave roller bearing is located at the end of the long leg. 9. Double sheave part according to claim 7 or 8, characterized in that the lifting device acting in a substantially horizontal direction is adapted to act approximately at the center of the long leg. 10. The double sheave part according to claim 1, wherein the upper sheave adjusting roller is arranged below the plane where the lower sheave is formed. 11. The double sheave part according to claim 1, wherein the upper sheave tensioning roller is arranged below the plane where the lower sheave is formed. 12. The highest point (P) of the upper sheave traveling course.
Is the diameter (D) of the sheave roller supported by the turning lever
Double sheave part according to any one of claims 1 to 9, characterized in that it is located approximately 1 to 2 times above the lower sheave forming plane (F). 13. The sheave runs from the region of the support bar to the forming roller in at least a substantially straight section.
Double sheave part described in section. 14. The sheave runs to the forming roller via an additional dewatering box which is raised downwards and which is located in the upper sheave.
Double sheave part according to any one of 2 to 2. 15. The sheave runs up to the forming roller via an additional dewatering box which is raised upwards and which is located in the lower sheave.
The double sheave portion according to any one of 2 above. 16. The double sheave part according to claim 1, wherein the sheave is paid out from the forming roller in a downward direction. 17. The double sheave part according to claim 1, wherein the sheave is paid out from the forming roller in an upward direction. 18. The inner sheave in the winding area of the forming roller forms a second double-sheave area on the upper side of the forming roller together with a third sheave, and additionally to the inlet wedge of this double-sheave area. 18. A raw material charging section is provided, and the inner sheave removes the web and guides it to a location.
The double sheave part shown.